There is a subtle race in the CPU hotplug code, where a CPU which has
been offlined can online itself before being requested, which results
in things going astray on the next online/offline cycle.

What happens in the normal online/offline/online cycle is:

	CPU0			CPU3
	requests boot of CPU3
	pen_release = 3
	flush cache line
				checks pen_release, reads 3
				starts boot
				pen_release = -1
	... requests CPU3 offline ...
				... dies ...
				checks pen_release, reads -1
	requests boot of CPU3
	pen_release = 3
	flush cache line
				checks pen_release, reads 3
				starts boot
				pen_release = -1

However, as the write of -1 of pen_release is not fully flushed back to
memory, and the checking of pen_release is done with caches disabled,
this allows CPU3 the opportunity to read the old value of pen_release:

	CPU0			CPU3
	requests boot of CPU3
	pen_release = 3
	flush cache line
				checks pen_release, reads 3
				starts boot
				pen_release = -1
	... requests CPU3 offline ...
				... dies ...
				checks pen_release, reads 3
				starts boot
				pen_release = -1
	requests boot of CPU3
	pen_release = 3
	flush cache line

Fix this by grouping the write of pen_release along with its cache line
flushing code to ensure that any update to pen_release is always pushed
out to physical memory.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

With "ARM: CPU hotplug: remove bug checks in platform_cpu_die()", we
now do not use hard_smp_processor_id(), we no longer need to read the
hardware processor ID.  Remove the include providing this function.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

platform_cpu_die() is entered from the CPU's own idle thread, which
can not be migrated to other CPUs.  Moreover, the 'cpu' argument
comes from the thread info, which will always be the 'current'
CPU.  So remove this useless bug check.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

We always need to wait for the dying CPU to reach a safe state before
taking it down, irrespective of the requirements of the platform.
Move the completion code into the ARM SMP hotplug code rather than
having each platform re-implement this.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

All platforms call trace_hardirqs_off() in their secondary startup code,
so move this into the core SMP code - it doesn't need to be in the
per-platform code.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

There is a certain amount of smp_prepare_cpus() which doesn't belong
in the platform support code - that is, code which is invariant to the
SMP implementation.  Move this code into arch/arm/kernel/smp.c, and
add a platform_ prefix to the original function.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Milo is an old boot loader, which is no longer relevant for these
platforms.  References to it are misleading.  Move the code out
of poke_milo(), and remove references to milo in comments.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

We don't need this small function as well as scu_get_core_count()
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

scu_get_core_count() never returns zero cores, so we don't need to
check and correct if ncores is zero.

Tegra was missing the check against NR_CPUS, leading to a potential
bitfield overflow if this becomes the case.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Ensure that the number of CPUs is sanity checked before setting
the number of possible CPUs.  This avoids any chance of overflowing
the cpu_possible bitmap.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This allows us to use smp_cross_call() to trigger a number of different
software generated interrupts, rather than combining them all on one
SGI.  Recover the SGI number via do_IPI.
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Since we're now using addruart to establish the debug mapping, we can
remove the io_pg_offst and phys_io members of struct machine_desc.

The various declarations were removed using the following script:

  grep -rl MACHINE_START arch/arm | xargs \
  sed -i '/MACHINE_START/,/MACHINE_END/ { /\.\(phys_io\|io_pg_offst\)/d }'

[ Initial patch was from Jeremy Kerr, example script from Russell King ]
Signed-off-by: NNicolas Pitre <nicolas.pitre@linaro.org>
Acked-by: Eric Miao <eric.miao at canonical.com>

Rather than checking the MMU status in every instance of addruart, do it
once in kernel/debug.S, and change the existing addruart macros to
return both physical and virtual addresses. The main debug code can then
select the appropriate address to use.

This will also allow us to retreive the address of a uart for the MMU
state that we're not current in.

Updated with fixes for OMAP from Jason Wang <jason77.wang@gmail.com>
and Tony Lindgren <tony@atomide.com>, and fix for versatile express from
Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>.
Signed-off-by: NJeremy Kerr <jeremy.kerr@canonical.com>
Signed-off-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: NJason Wang <jason77.wang@gmail.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>
Tested-by: NKevin Hilman <khilman@deeprootsystems.com>

Provide a common header to read the SMP CPU number from the MPIDR.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

On some platforms, the GPIO value from the gpio_cd pin doesn't need to
be inverted to get it active high.  Add a cd_invert platform data
parameter and change existing platforms using GPIO for CD (only
Realview) to enable it.
Acked-by: NLinus Walleij <linus.walleij@stericsson.com>
Signed-off-by: NRabin Vincent <rabin.vincent@stericsson.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The patch to add the apb_pclk to the AMBA/PrimeCell bus broke
RealView, since the clockdevice is not registered at probe() time.
This moves clock initialization to a core_initcall()

[rmk:moved before the problematical commit to avoid bisect problems]
Signed-off-by: NLinus Walleij <linus.walleij@stericsson.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The MMC card detection sense has become really confused with negations
at various levels, leading to some platforms not detecting inserted
cards.  Fix this by converting everything to positive logic throughout,
thereby getting rid of these negations.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Add a dummy clk definition for the APB pclk signal on all platforms
using the AMBA bus infrastructure.  This ensures that these platforms
continue to work when the core amba bus code controls the APB pclk.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This adds some platform data for the character LCD found in the
RealView and Versatile reference designs from ARM.
Signed-off-by: NLinus Walleij <triad@df.lth.se>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Since we no longer support discontigmem, node is always zero, so
remove this argument.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This adds platform data for the PL022 to the ARM RealView reference
designs, adds the necessary clock definition and fixes a badly
defined IRQ line on the PB1176.
Signed-off-by: NLinus Walleij <linus.walleij@stericsson.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This is a number of basic fixes to the PB1176 that makes it tick
properly:

- Detect MMC insertion/removal even when PL061 GPIO is not compiled
  in. The register to read this status directly is removed on the
  PB1176.
- Define the UART3 on the DevChip (where is actually is) and define
  the new UART4 serial port on the FPGA.
- Also define the clocks for these two UARTs apropriately.
- Remove the false notion that the PB1176 should have its CLCD
  on the ISSP, this is not the case, it is in the DevChip.
- Remove the defintions and the previously commented-out PL081
  DMAC. As confirmed by mail this was found to be broken on the
  PB1176 board and removed from the subsequent FPGA images.
Signed-off-by: NLinus Walleij <linus.walleij@stericsson.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

RealView boards with certain revisions of the L220 cache controller (ARM11*
processors only) may have issues (hardware deadlock) with the recent changes to
the mb() barrier implementation (DSB followed by an L2 cache sync). The patch
redefines the RealView ARM11MPCore mandatory barriers without the outer_sync()
call.

Cc: <stable@kernel.org>
Tested-by: NLinus Walleij <linus.walleij@stericsson.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

When not aligned, random bits could be written in the initial page table
by the __create_page_tables() function.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Consistently name all SMP platform related functions.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This patch updates the initialisation routines for the Realview boards
and the Versatile Express board [ca9x4 tile] so that they register their
PMU IRQs with the PMU framework in the Kernel.
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

In anticipation of PMU support for Realview boards, the IRQs defined
for some of these boards need updating.

This patch removes incorrect L220 IRQ definitions, corrects incorrect PMU
IRQs and adds any missing IRQs that are required.
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Provide a common sched_clock() implementation for Versatile and
Realview.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The only difference between ICST307 and ICST525 are the two arrays
for calculating the S parameter; the code is now identical.  Merge
the two files and kill the duplicated code.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This makes the ICST support fit more nicely with the clk API,
eliminating the need to *1000 and /1000 in places.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The structures for the ICST307 and ICST525 VCO devices are
identical, so merge them together.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The switch to using GPIOLIB broke the sd/mmc card detection on the
RealView development boards if GPIO_PL061 was not selected.
This patch selects GPIO_PL061 if GPIOLIB is selected.
The sense of the return value from mmc_status has also changed
and is corrected.
Signed-off-by: NColin Tuckley <colin.tuckley@arm.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>